scholarly journals Cortical Responses to the Amplitude Envelopes of Sounds Change with Age

2020 ◽  
Author(s):  
Vanessa C. Irsik ◽  
Ala Almanaseer ◽  
Ingrid S. Johnsrude ◽  
Björn Herrmann
Keyword(s):  
Older Adults ◽  
Auditory Cortex ◽  
Cortical Excitability ◽  
Neural Synchronization ◽  
Speech In Noise ◽  
Age Related ◽  
Cortical Responses ◽  
Sound Features ◽  
Experience Difficulty ◽  
Age Related Changes

AbstractMany older listeners have difficulty understanding speech in noise, when cues to speech-sound identity are less redundant. The amplitude envelope of speech fluctuates dramatically over time, and features such as the rate of amplitude change at onsets (attack) and offsets (decay) signal critical information about the identity of speech sounds. Aging is also thought to be accompanied by increases in cortical excitability, which may differentially alter sensitivity to envelope dynamics. Here, we recorded electroencephalography in younger and older human adults (of both sexes) to investigate how aging affects neural synchronization to 4-Hz amplitude-modulated noises with different envelope shapes (ramped: slow attack & sharp decay; damped: sharp attack & slow decay). We observed that subcortical responses did not differ between age groups, whereas older compared to younger adults exhibited larger cortical responses to sound onsets, consistent with an increase in auditory cortical excitability. Older adults showed increased neural synchronization when the envelope shape was damped compared to ramped, whereas younger participants showed the opposite pattern. Furthermore, the response shape of synchronized neural activity was more sinusoidal in younger individuals, whereas synchronized activity in older adults was less sinusoidal and more peaked. The current results suggest that age-related changes in the excitability of auditory cortex alter responses to envelope dynamics, and this may be part of the reason why older adults experience difficulty understanding speech in noise.Significance StatementMany adults above age 50 report difficulty understanding speech when there is background noise, which can trigger social withdrawal and negative psychosocial health outcomes. The difficulty may be related to age-related changes in how the brain processes temporal sound features. We tested younger and older people on their sensitivity to different envelope shapes, using EEG. Our results demonstrate that aging is associated with heightened sensitivity to sounds with a sharp attack and gradual decay, and sharper neural responses that deviate from the sinusoidal features of the stimulus, perhaps reflecting increased excitability in the aged auditory cortex. Altered responses to temporal sound features may be part of the reason why older adults often experience difficulty understanding speech in social situations.

scholarly journals A Neural Signature of Regularity in Sound is Reduced in Older Adults

2021 ◽  
Author(s):  
Björn Herrmann ◽  
Burkhard Maess ◽  
Ingrid S. Johnsrude
Keyword(s):  
Older Adults ◽  
Auditory Cortex ◽  
Older Individuals ◽  
Sound Perception ◽  
Younger Adults ◽  
Sound Processing ◽  
Age Related ◽  
Increased Sensitivity ◽  
Neural Signature ◽  
Age Related Changes

AbstractSensitivity to repetitions in sound amplitude and frequency is crucial for sound perception. As with other aspects of sound processing, sensitivity to such patterns may change with age, and may help explain some age-related changes in hearing such as segregating speech from background sound. We recorded magnetoencephalography to characterize differences in the processing of sound patterns between younger and older adults. We presented tone sequences that either contained a pattern (made of a repeated set of tones) or did not contain a pattern. We show that auditory cortex in older, compared to younger, adults is hyperresponsive to sound onsets, but that sustained neural activity in auditory cortex, indexing the processing of a sound pattern, is reduced. Hence, the sensitivity of neural populations in auditory cortex fundamentally differs between younger and older individuals, overresponding to sound onsets, while underresponding to patterns in sounds. This may help to explain some age-related changes in hearing such as increased sensitivity to distracting sounds and difficulties tracking speech in the presence of other sound.

scholarly journals Representation of speech in noise in the aging midbrain and cortex: aging may dominate over hearing-loss

2017 ◽  
Author(s):  
Alessandro Presacco ◽  
Jonathan Z. Simon ◽  
Samira Anderson
Keyword(s):  
Older Adults ◽  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Temporal Processing ◽  
Normal Hearing ◽  
Sensorineural Hearing ◽  
Speech In Noise ◽  
Age Related ◽  
Cortical Responses ◽  
Processing Deficits

ABSTRACTObjectiveTo understand the effect of peripheral hearing loss on the representation of speech in noise in the aging midbrain and cortex.MethodsSubjects comprised 17 normal-hearing younger adults, 15 normal-hearing older adults and 14 hearing-impaired older adults. The midbrain response, measured with Frequency-Following Responses (FFRs), and the cortical response, measured with magnetoencephalography (MEG) responses, were recorded from subjects listening to speech in quiet and noise at varying signal to noise ratios (SNRs).ResultsBoth groups of older listeners showed both weaker midbrain response amplitudes and overrepresentation of cortical responses compared to younger listeners. However, significant differences between the older groups were found in both midbrain-cortex relationships and in cortical processing durations, suggesting that hearing loss may alter reciprocal connections between lower and higher levels of the auditory pathway.ConclusionsThe paucity of differences in midbrain or cortical responses between the two older groups suggest that age-related temporal processing deficits may contribute to older adults’ communication difficulties beyond what might be predicted from peripheral hearing loss alone.SignificanceClinical devices, such as hearing aids, should not ignore age-related temporal processing deficits in the design of algorithms to maximize user benefit.HIGHLIGHTSMild sensorineural hearing loss does not appear to significantly exacerbate already appreciable age-related deficits in midbrain speech-in-noise encoding.Mild sensorineural hearing loss also does not appear to significantly exacerbate already appreciable age-related deficits in most measures of cortical speech-in-noise encoding.Central processing deficits caused by peripheral hearing loss in older adults are seen only in more subtle measures, including altered relationships between midbrain and cortex.

scholarly journals Recovery of functional and structural age-related changes in the rat primary auditory cortex with operant training

2010 ◽  
Vol 107 (31) ◽  
pp. 13900-13905 ◽  
Author(s):  
E. de Villers-Sidani ◽  
L. Alzghoul ◽  
X. Zhou ◽  
K. L. Simpson ◽  
R. C. S. Lin ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Primary Auditory Cortex ◽  
Age Related ◽  
Age Related Changes ◽  
Operant Training

scholarly journals Age-Related Changes in Molecular and Whole Muscle Function: Role of Fat Content?

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 141-141
Author(s):  
Joseph Gordon III ◽  
Nicholas Remillard ◽  
Chad Straight ◽  
Rajakumar Nagarajan ◽  
Bruce Damon ◽  
...  
Keyword(s):  
Older Adults ◽  
Molecular Mechanisms ◽  
Fat Content ◽  
Fat Deposition ◽  
Muscle Size ◽  
Type I ◽  
Contraction Velocity ◽  
Age Related ◽  
Whole Muscle ◽  
Age Related Changes

Abstract Decreases in muscle size and function are a general consequence of old age; the precise mechanisms of these changes remain unclear. Recent studies suggest that fat deposition in muscle may also contribute to dysfunction in older adults. Fat content was quantified in the quadriceps, and its effects on function in healthy young (21-45 y) and older (65-75 y) men and women (n=44) of comparable physical activity were compared. A subset of the young matched with the older group for muscle fat content were also examined. Peak fat-free whole muscle cross-sectional area (mCSA; cm2), volume (MV; cm3), fat content (fat fraction, FF; %), specific torque (Nm/mCSA) and peak contraction velocity (Nm∙s-1) were determined using fat-water magnetic resonance imaging and dynamometry (0-300□∙s-1). To examine potential molecular mechanisms of muscle weakness, vastus lateralis biopsies were obtained (n=31) and cross-bridge kinetics of type I and II fibers were determined. FF was higher in older adults than young (8.4±1.2% (SE), 7.6±1.4; p=0.03), while mCSA (48.9±10.4 vs. 64.2±17.3), MV (1536±532 vs. 2112±708), specific torque (2.6±0.4 vs. 3.2±0.4), and peak voluntary contraction velocity (422±20 vs. 441±23) were lower in older than young (p<0.01). Type II fiber myosin attachment rate was slower and attachment time longer in older muscle (p<0.017), providing a potential mechanism for the slowing of peak contraction velocity with age. Notably, differences at the whole muscle and molecular levels remained for the subset of young and older groups matched for FF, suggesting that fat deposition in muscle does not exacerbate age-related changes in function.

scholarly journals Developing a recovery-focused therapy for older people with bipolar disorder: a qualitative focus group study

BMJ Open ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. e049829
Author(s):  
Elizabeth Tyler ◽  
Fiona Lobban ◽  
Rita Long ◽  
Steven H Jones
Keyword(s):  
Older Adults ◽  
Bipolar Disorder ◽  
Focus Group ◽  
Older People ◽  
Focus Groups ◽  
Later Life ◽  
Focus Group Study ◽  
Age Related ◽  
Health Related ◽  
Age Related Changes

ObjectivesAs awareness of bipolar disorder (BD) increases and the world experiences a rapid ageing of the population, the number of people living with BD in later life is expected to rise substantially. There is no current evidence base for the effectiveness of psychological interventions for older adults with BD. This focus group study explored a number of topics to inform the development and delivery of a recovery-focused therapy (RfT) for older adults with BD.DesignA qualitative focus group study.SettingThree focus groups were conducted at a university in the North West of England.ParticipantsEight people took part in the focus groups; six older adults with BD, one carer and one friend.ResultsParticipant’s responses clustered into six themes: (1) health-related and age-related changes in later life, (2) the experience of BD in later life, (3) managing and coping with BD in later life, (4) recovery in later life, (5) seeking helping in the future and (6) adapting RfT for older people.ConclusionsParticipants reported a range of health-related and age-related changes and strategies to manage their BD. Participants held mixed views about using the term ‘recovery’ in later life. Participants were in agreement that certain adaptations were needed for delivering RfT for older adults, based on their experience of living with BD in later life. The data collected as part of the focus groups have led to a number of recommendations for delivering RfT for older adults with BD in a randomised controlled trial (Clinical Trial Registration: ISRCTN13875321).

scholarly journals Losing touch: age-related changes in plantar skin sensitivity, lower limb cutaneous reflex strength, and postural stability in older adults

2016 ◽  
Vol 116 (4) ◽  
pp. 1848-1858 ◽  
Author(s):  
Ryan M. Peters ◽  
Monica D. McKeown ◽  
Mark G. Carpenter ◽  
J. Timothy Inglis
Keyword(s):  
Older Adults ◽  
Lower Limb ◽  
Postural Stability ◽  
Tibialis Anterior ◽  
Tibialis Anterior Muscle ◽  
Quiet Standing ◽  
Detection Thresholds ◽  
Cutaneous Reflex ◽  
Age Related ◽  
Age Related Changes

Age-related changes in the density, morphology, and physiology of plantar cutaneous receptors negatively impact the quality and quantity of balance-relevant information arising from the foot soles. Plantar perceptual sensitivity declines with age and may predict postural instability; however, alteration in lower limb cutaneous reflex strength may also explain greater instability in older adults and has yet to be investigated. We replicated the age-related decline in sensitivity by assessing monofilament and vibrotactile (30 and 250 Hz) detection thresholds near the first metatarsal head bilaterally in healthy young and older adults. We additionally applied continuous 30- and 250-Hz vibration to drive mechanically evoked reflex responses in the tibialis anterior muscle, measured via surface electromyography. To investigate potential relationships between plantar sensitivity, cutaneous reflex strength, and postural stability, we performed posturography in subjects during quiet standing without vision. Anteroposterior and mediolateral postural stability decreased with age, and increases in postural sway amplitude and frequency were significantly correlated with increases in plantar detection thresholds. With 30-Hz vibration, cutaneous reflexes were observed in 95% of young adults but in only 53% of older adults, and reflex gain, coherence, and cumulant density at 30 Hz were lower in older adults. Reflexes were not observed with 250-Hz vibration, suggesting this high-frequency cutaneous input is filtered out by motoneurons innervating tibialis anterior. Our findings have important implications for assessing the risk of balance impairment in older adults.

scholarly journals Auditory word recognition across the lifespan

2016 ◽  
Vol 6 (1-2) ◽  
pp. 119-146 ◽  
Author(s):  
Henrike K. Blumenfeld ◽  
Scott R. Schroeder ◽  
Susan C. Bobb ◽  
Max R. Freeman ◽  
Viorica Marian
Keyword(s):  
Older Adults ◽  
Cognitive Control ◽  
Cognitive Processes ◽  
Processing Speed ◽  
Word Identification ◽  
Age Related ◽  
Auditory Word ◽  
Auditory Word Recognition ◽  
The Relationship ◽  
Age Related Changes

Abstract Recent research suggests that bilingual experience reconfigures linguistic and nonlinguistic cognitive processes. We examined the relationship between linguistic competition resolution and nonlinguistic cognitive control in younger and older adults who were either bilingual or monolingual. Participants heard words in English and identified the referent among four pictures while eye-movements were recorded. Target pictures (e.g., cab) appeared with a phonological competitor picture (e.g., cat) and two filler pictures. After each eye-tracking trial, priming probes assessed residual activation and inhibition of target and competitor words. When accounting for processing speed, results revealed that age-related changes in activation and inhibition are smaller in bilinguals than in monolinguals. Moreover, younger and older bilinguals, but not monolinguals, recruited similar inhibition mechanisms during word identification and during a nonlinguistic Stroop task. Results suggest that, during lexical access, bilinguals show more consistent competition resolution and recruitment of cognitive control across the lifespan than monolinguals.

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